Safe tampering indicating means



Dec. 13, 1955 H. EVANS SAFE TAMPERING INDICATI NG MEANS Filed Aug. 2, 1954 INVENTOR. Harold fmzns fl-Z-ZaT-ney,

United States Patent (3 SAFE TAMPERING INDICATING MEANS Harold Evans, Niagara Falls, Ontario, Canada Application August 2, 1954, Serial No. 447,170

3 Claims. (Cl. 116-114) This invention relates to safes and more particularly to means for indicating unauthorized entry into or tampering with safes.

A frequent unauthorized manner of obtaining valuable information from safes, and particularly file safes, is performed by drilling through the dial on the safe, extracting desired information from the contents of the safe, and replacing the drilled dial by a new dial. In this manner, no indication of the fact that such information has been extracted occurs and thus no steps can be taken to circumvent improper use of the extracted information.

An object of the present invention is to provide means for positively indicating unauthorized entry into safes whereby immediate steps may be taken to avoid, to all possible extent, the consequences of unauthorized use of the extracted information.

The invention will be described with reference to the accompanying drawing, in which:

Figure -l is a sectional plan view of a safe door having the invention incorporated therein, and

Figure 2 is a front elevation of the safe door.

In the drawing, 1 indicates a safe of conventional structure and 2, the safe door.

The door 2 is of generally standard construction and includes a forward panel 3, rear panel 4, edge panel 5, lock box 6, lock 7, dial 8 having spindle 9 extending through tube 10 in the lock box, and handle 11 having spindle 12 extending through tube 13 in the lock box.

In accordance with the invention, a sheet of tempered glass 14 is interposed between the forward panel 3 of the door and the front plate 15 of the lock box, the glass sheet 14 being mounted within a steel or like frame 16 secured to the edge portion of the front plate 15. The glass sheet 14, as shown, overlies the major portion of the front plate 15 and extends substantially beyond the dial, handle and their spindles. The spindle tubes 10 and 12 thus extend through the glass sheet. The edges of the glass sheet are preferably in slightly spaced relation to frame 16 and tubes 10 and 12 to permit variations in expansion of materials.

A characteristic of a sheet of tempered glass is that, while it possesses great mechanical strength, it will not withstand drilling or puncturing. Thus, drilling of a hole through any portion of a tempered glass sheet results in complete shattering of the sheet into relatively small pieces. This shattering occurs in generally uniform degree throughout the area of the sheet. This phenomenon is utilized in the practice of the present invention. Thus, drilling of a hole through the dial and door to provide access to the lock mechanism will necessitate drilling through the glass sheet 14, which thereupon will shatter.

It will, of course, be understood that the holes 14a and 14b in the glass sheet 14 for passage of the spindle tubes will be formed therein during moulding of the sheet, or otherwise before tempering thereof.

Means are provided for exposing to view a portion (which may be any portion) of the glass sheet 14 whereby shattering thereof will at once be apparent. Such means comprises a window 17 which may be composed of a sheet or disc 18 of transparent plastic or the like such as, for instance, methyl methacrylate. The disc 18 may be mounted on the forward panel 3 of the door by means of a flanged ring 19 which is fastened to the panel 3 by means, such as screws 20, inaccessible from the outside of the panel. The disc 18 overlies an opening 21 in door panel 3 whereby a portion of the glass sheet is exposed through the transparent disc. The size of window 17 may vary but a viewing area of approximately three inch diameter is satisfactory.

The dimensions of the glass sheet 14 may also vary within wide limits but preferably it should overlie the front plate of the lock box substantially completely. Thus, it may be only about one inch smaller in each dimension than the plate 15 to provide mounting of the surrounding frame 16. The thickness of the sheet 14 need not be substantially greater than one-quarter inch.

It will thus be apparent that shattering of the glass plate 14, as by unauthorized drilling thereof, will provide an immediately visible indication of any tampering with the safes contents, as a result of such drilling, by the multiplicity of cracks in the portion of glass visible through window 17. Since the transparent disc 18 is extremely diflicult to remove and replace without detection because of the concealed fastening means, undetected tampering with the window is substantially avoided. It is further proposed to paint the portion of glass sheet exposed through the window with the same color of paint as that on the face of forward door panel 3.

I claim:

1. In a safe having a forward door panel, and a dial on said panel having a spindle extending therethrough, means for indicating unauthorized tampering with said safe comprising a tempered glass sheet underlying said panel and extending beyond the periphery of said dial, said glass sheet having a hole therein through which said spindle extends, and a window in said panel exposing to view a portion of said glass sheet, said sheet being shatterable substantially uniformly throughout its extent in response to drilling or puncturing thereof thereby to provide an indication of such shattering through said window.

2. In a safe having a forward door panel, and a lock box having a front plate and dial and handle spindle tubes carried by the plate, means for indicating unauthorized tampering with said safe comprising a sheet of tempered glass disposed between said door panel and front plate and extending over the major portion of said front plate, said sheet having holes therein through which said spindle tubes extend, and a window in said panel exposing to view a portion of said glass sheet, said sheet being shatterable substantially uniformly throughout its extent in response to drilling or puncturing thereof thereby to provide an indication of such shattering through said window.

3. In a safe as defined in claim 1, wherein said window comprises a sheet of transparent plastic material, a frame carrying said transparent sheet and concealed fastening means securing said frame to said panel, said panel having an opening underlying said transparent sheet.

References Cited in the file of this patent UNITED STATES PATENTS 2,319,473 Podjus May 18, 1943 Little Apr. 1, 1873 

